WO2017038408A1

WO2017038408A1 - Coal storage system and coal storage method

Info

Publication number: WO2017038408A1
Application number: PCT/JP2016/073483
Authority: WO
Inventors: 誠籔内; 貴寛松延; 朋之仲谷; 太郎加藤
Original assignee: 宇部興産株式会社
Priority date: 2015-08-28
Filing date: 2016-08-09
Publication date: 2017-03-09
Also published as: JP6870614B2; JPWO2017038408A1; CN108137234A

Abstract

The present invention provides a coal storage system and a coal storage method which achieve adequate temperature control at a low cost without significantly increasing the water content of coal. This coal storage system is provided with: a coal yard 2 for storing the coal; a pyramid-shaped coal pile 1 formed in the coal yard and having a ceiling surface 11 and an outer peripheral side surface 12; a compactor for compacting the coal pile 1; and a sprinkler 3 for sprinkling water on the coal pile. The coal pile 1 has at least the outer peripheral section of the ceiling surface 11 compacted by the compactor, and the outer peripheral side surface 12 sprinkled with water by the sprinkler 3.

Description

Coal storage system and coal storage method

The present invention relates to a coal storage system and a coal storage method.

Conventionally, since coal easily oxidizes and generates heat, it is common to control the temperature by watering or the like when storing the coal. As such a technique, Patent Document 1 discloses that coal is stored in a state in which 50% or more of its total height is submerged to suppress heat generation, and the stored coal is taken out in a wet state, It is disclosed that coal is heated and dried with extracted steam generated from a power generation facility.

Patent Document 1: Japanese Patent Application Laid-Open No. 2015-055375

However, the technique disclosed in Patent Document 1 significantly increases the water content of coal by submerging the coal. The problem is that the process from drying such coal with increased water content with extracted steam to making it possible to use the stored coal is complicated and may increase the cost of the coal. was there. In addition, since the extraction steam from the power generation facility is used to dry the coal, there is a problem that the storage place of the coal is limited to a place adjacent to the power generation facility.

The present invention has been made to solve the above-described problems, and an object of the present invention is to realize appropriate temperature management without significantly increasing the water content, and to achieve a low-cost coal storage system and coal storage. It is to provide a method.

The coal storage system of the present invention includes a yard for storing coal,
A frustum-shaped coal pile having a ceiling surface and an outer peripheral side surface formed by stacking the coal in the yard;
An expansion facility for expanding the coal pile;
A sprinkler for watering the coal pile;
With
The coal pile is characterized in that at least an outer peripheral portion of the ceiling surface is expanded by the pressure expansion equipment, and the outer peripheral side surface is sprinkled by the sprinkler.

In addition, the present invention provides a coal storage method, the coal storage method of forming a frustum-shaped coal pile having a ceiling surface and an outer peripheral side surface by stacking coal in a yard;
Expanding the outer peripheral portion of at least the ceiling surface of the coal pile;
Watering the outer circumferential side of the coal pile that has been spread;
Have

(Definition of terms)
In the present invention, “expanding pressure” means that the surface of a coal pile during or after formation is pressed and pressed to such an extent that the internal voids can be reduced.

“Expanding equipment” refers to general equipment used to spread coal piles. The “heavy machinery” can be used simply as “expanding equipment”, but other weights that have a flat bottom surface, and weights that move up and down to pressurize the weight against the surface of the coal pile. A combination with a vertical movement device can also be used as the “expanding pressure equipment”. “Heavy machinery” is a general term for construction machinery. Among “heavy machinery”, “construction vehicles” can perform “expanding pressure” by simply running on the surface of the coal pile using its own weight. When a power shovel is used as a “heavy machine”, “developing pressure” can be performed by pressing or hitting the bucket or backhoe on the surface of the coal pile. This is effective in the case of “expanding pressure” where a “heavy machine” cannot travel. Furthermore, a “compacting machine” that is a kind of “heavy machinery” can be used for the spreading pressure.

In the present invention, the expansion pressure specifying the coal pile portion of the “expansion pressure” is defined as follows.

“Outer periphery pressure” means that only the area 3 to 5 m from the position 1 to 2 m inside from the outer periphery of the ceiling surface of the coal pile is applied.

“Surface pressure” refers to spreading the entire ceiling surface of the coal pile. Therefore, in the “surface spreading pressure”, in addition to the area spread by the “outer circumferential spreading pressure”, the inner area and the outer area are further spread. Further, in the “surface spreading pressure”, the outer edge portion of the coal pile ceiling surface (corresponding to “shoulder shoulder” in civil engineering terms) is formed in a substantially round shape.

“Corner spreading pressure” refers to the spreading of the corner (the portion corresponding to the side ridge of the truncated pyramid) on the outer circumferential side of the coal pile. At this time, it is preferable to apply pressure so that the corners are formed substantially round. When performing “corner spreading pressure” with heavy machinery, heavy machinery cannot run on the outer circumferential side of the coal pile, but the corners are spread by pressing or hitting the bucket or backhoe against the corner. Can do.

According to the present invention, an appropriate temperature control can be realized without significantly increasing the water content of coal, and a low-cost coal storage system and method can be provided.

It is a top view of the coal pile by one Embodiment of this invention. It is a side view of the coal pile shown in FIG. It is a figure which shows the surface angle spread pressure in the coal pile shown in FIG. 1 is a schematic top view of a coal pile in Example 1. FIG. It is a graph which shows the correlation of the temperature of the coal pile in Example 1, and watering. It is a graph which shows the correlation of the water | moisture content of a coal pile and watering in Example 1 of this invention. It is a schematic top view of the coal pile in Example 2. It is a graph which shows the correlation with the temperature of the coal pile in Example 2, and watering. It is a graph which shows the correlation of the water | moisture content of the coal pile in Example 2, and watering. It is a graph which shows transition of the average temperature of a coal pile in Example 3, and a water | moisture content. It is a graph which shows transition of the maximum temperature of a coal pile in Example 3, and a water | moisture content. It is a schematic top view of the coal pile in the comparative example 1. It is a graph which shows the temperature transition of the coal pile in the comparative example 1. It is a schematic top view of the coal pile in the comparative example 2. It is a graph which shows transition of the average temperature of coal pile in comparative example 2, and the maximum temperature. It is a schematic top view of the coal pile in the comparative example 3. It is a graph which shows transition of the maximum temperature of the coal pile in the comparative example 3.

1 and 2, there are shown a top view and a side view of a coal pile 1 constituting a part of a coal storage system according to an embodiment of the present invention. The coal pile 1 is obtained by depositing coal on a coal yard 2 and usually has a ceiling surface 11 which is a substantially horizontal plane and a ceiling so that the entire vertical cross section is a truncated cone shape having a substantially trapezoidal shape. The outer peripheral side surface 12 is configured to continuously extend from the edge of the surface and incline in a skirt-like manner. The coal pile 1 is spread and sprinkled to suppress heat generation. A spreading machine such as a heavy machine is used for spreading the coal pile 1, and a sprinkler is used for watering. Therefore, in addition to the coal pile 1, the coal storage system includes an expansion facility and a sprinkler.

The following describes these pressure spreading, watering, and other configurations.

[Extended pressure]
The coal pile 1 can be formed by shaping the surface of coal stacked by a stacker using a pressure-extended equipment such as a heavy machine. The coal pile 1 that has been stacked and formed reduces internal voids by spreading pressure, thereby suppressing the oxidation and heat generation of coal. The coal pile 1 can be formed, for example, by repeating the steps of stacking and stacking coal to a height of about 2 m, and then stacking and stacking 2 m. Expanding pressure can be performed by a heavy machine applying a load on the ceiling surface 11 that is the upper surface of the coal pile 1, further stacking coal on the expanded ceiling surface 11 and further expanding the coal. Thus, the coal pile 1 having a desired size can be formed.

At the time of spreading pressure, the entire ceiling surface 11 may be spread (surface spreading pressure) or only the ceiling surface outer peripheral portion 13 may be spread (outer circumferential spreading pressure). However, the expansion pressure of the outer peripheral portion 13 of the ceiling surface is essential. The reason is that the oxidation and heat generation of the coal pile 1 proceeds by the air flowing into the coal pile 1 from the outer peripheral side surface 12, but by spreading the ceiling surface outer peripheral portion 13, This is because the density of coal becomes high and air hardly flows in from the outer peripheral side surface 12. In addition, when the heavy machinery is too close to the end 15 of the ceiling surface at the time of expanding the ceiling surface outer peripheral portion 13, the heavy machinery may fall from the coal pile 1. Therefore, by providing the ceiling surface outer peripheral portion 13 for performing pressure expansion on the inner peripheral side with respect to the end portion 15, the passage of the heavy machinery is secured.

The coal pile 1 can have a roadway 14 as a route for moving heavy machinery from the coal yard 2 to the ceiling surface 11 of the coal pile 1 in a part of the outer peripheral side surface 12. The shape and position of the roadway 14, that is, the route of heavy machinery can be arbitrary. For example, as in FIG. 1, the roadway 14 is provided on the diagonal of the coal pile 1 when the coal pile 1 is viewed from above. Alternatively, as shown in FIG. 4 to be described later, the road 14 may be deviated from the diagonal line.

The outer peripheral side surface 12 of the coal pile 1 is formed by the accumulated coal flowing down to the periphery of the ceiling surface 11. Further, since it is difficult for the heavy machinery to travel stably on the outer peripheral side surface 12 except for the roadway 14, normally, no pressure is applied to the outer peripheral side surface 12.

[Watering]
Coal, especially sub-bituminous coal and lignite (including reformed coal of lignite), which is likely to oxidize and generate heat, is sprinkled onto the coal pile 1 by the sprinkler 3 (see FIG. 1) during storage. In the coal pile 1, since air flows in from the outer peripheral side surface 12, the vicinity of the outer peripheral side surface 12 is most likely to oxidize and generate heat. Therefore, heat generation can be efficiently suppressed by watering at least the outer peripheral side surface 12.

Even in the case of water spraying only on the outer peripheral side surface 12, the oxidation and heat generation of the coal pile 1 can be suppressed. In this case, compared to the case of watering the entire coal pile 1, the increase in coal moisture and the increase in the amount of water spray are suppressed. be able to. The sprinkler 3 may be installed at any position and number as long as the sprinkler 3 can be sprayed on a desired region of the outer peripheral side surface 12, for example, the position and number shown in FIG. 1.

Sprinkling is not continuous watering but regular watering such as how many hours per day is sufficient. By combining the spreading pressure and watering, it is possible to sufficiently suppress the heat generation and moisture increase of coal. In addition, with respect to the frequency of watering, the frequency of watering after that can be reduced to, for example, half compared to the frequency of watering from the start of coal storage to the 10th to 14th days. The Furthermore, it is possible to suppress the heat generation of coal within about 1 to 2 months from the start of coal storage without watering.

[Corner spreading pressure]
In FIG. 3, the example of the spreading pressure to the surface corner | angular part in the coal pile 1 is shown. For simplification of explanation, the roadway 14 is omitted in FIG. Since the coal pile 1 is formed by stacking massive coal, air easily flows into the vicinity of the corner 16 and the coal is easily oxidized. In particular, the corner 16 of the coal pile 1 (in the example shown in FIG. 2, the coal pile 1 is a substantially quadrangular pyramid, and the corner 16 corresponds to the vicinity of the surrounding four sides). Is particularly large. Therefore, the corner 16 of the outer periphery of the coal pile 1 is spread with a heavy machine to reduce the amount of air flow by the wind, thereby suppressing the oxidation of the coal.

[Other configurations]
The coal pile 1 may be sprayed with chemicals as necessary. The spraying of the chemical may be performed on the entire surface of the coal pile 1 after the coal pile 1 is formed, or may be performed on the coal before forming the coal pile 1. Examples of the chemical include a surfactant for imparting hydrophilicity to coal and a coating agent for maintaining the shape of the coal pile 1. When the surfactant is sprayed, it is preferable to spray the coal before the coal pile 1 is formed in order to make the coal pile 1 hydrophilic. On the other hand, when the coating agent is sprayed, it is sufficient that the surface of the coal pile 1 is coated.

When the chemical is sprayed in this way, the coal storage system can further include an appropriate chemical spraying facility according to the chemical to be sprayed.

The effect of suppressing the heat generation of the coal pile 1 was evaluated by Examples 1 to 3 and Comparative Examples 1 to 3. Table 1 shows the properties of the coal used in these examples and comparative examples.

Example 1
In FIG. 4, the schematic top view of the coal pile 1 in Example 1 is shown. The coal pile 1 was formed by repeatedly stacking coal with a stacker and forming the surface of the stacked coal with a heavy machine. In FIG. 4, the illustration of the outer peripheral portion 13 of the ceiling surface is omitted.

In Example 1, hydrophilicity was improved by spraying a surfactant on coal pile 1 (coal storage amount of about 30,000 tons) formed on coal yard 2. Surfactant spraying was performed using a chemical spraying facility installed in the unloader feeding feeder portion of the coal before being stacked on the stacker. As the surfactant, a publicly known one (manufactured by NOF Corporation, Dasseal F-10) was used.

After the coal pile 1 was formed, only the outer peripheral portion 13 of the ceiling surface was spread out with a heavy machine. Further, the corner portion 16 was expanded by hitting the surface with a heavy machine (bucket or backhoe of a power shovel) to form a round shape. Watering was performed only on the outer peripheral side surface 12. In addition, a thermocouple is installed as a temperature measuring device at the position indicated by the encircled numerals 1 to 16 in FIG. 4 on the outer peripheral side surface 12 and the temperature at each position is measured. did. Specifically, the thermocouple was inserted into the coal pile 1 at a position where the surface of the coal pile 1 was 3 m higher than the ground (coal yard 2). The insertion depth of the thermocouple into the coal pile 1 was 1.5 m, and the distance between the thermocouples in the horizontal direction was 10 m.

FIG. 5 is a graph showing the correlation between the temperature of the coal pile 1 and watering in Example 1. In the graph of FIG. 5, one scale on the horizontal axis indicates 10 days. In Example 1, water was sprayed almost uniformly on the outer peripheral side surface 12. The amount of water spray in Example 1 is shown in Table 2 below.

In addition, all the above days are days from the start date of coal storage. The same applies to the examples and comparative examples described below. As shown in FIG. 5, the temperature of the coal pile 1 in Example 1 is always below 60 ° C., which is the upper limit of the management temperature in coal storage, and heat generation of the coal pile 1 is suppressed by watering only the outer peripheral side surface 12. It was shown that

Moreover, in Example 1, the outer periphery moisture of the coal pile 1 was measured in order to confirm the transition of the moisture of the coal pile 1 due to sprinkling or rain. The peripheral moisture was measured as follows. The four outer peripheral sides 12 of the coal pile 1 are each divided into two areas in the horizontal direction. From a total of eight areas, three per one area at a position of 40 cm in height from the ground surface and 30 cm in depth from the outer peripheral side surface 12. A sample was taken. The collected samples were mixed, and the moisture measured on the mixed sample was used as the outer peripheral moisture of the coal pile 1.

The correlation between the moisture of the coal pile 1 and watering in Example 1 is shown in the graph of FIG. Also in the graph of FIG. 6, as in FIG. 5, one scale on the horizontal axis indicates 10 days. The vertical axis also shows rainfall. In Example 1, since water is sprayed only on the outer peripheral side surface 12, even if there is rain, the increase in moisture is only a few percent increase from the moisture (acceptance moisture) at the start of coal storage. Thereby, in Example 1, it can be said that heat_generation | fever is suppressed, without increasing the water | moisture content of coal more than necessary.

In addition, although not used in Example 1, in order to maintain the shape of the coal pile 1, a known coating agent may be sprayed. The coating agent also has a dust suppressing effect (see, for example, JP-A-7-117823 and JP-A-2000-80356), and the spraying of the coating agent can further suppress the oxidation and heat generation of the coal pile 1. In Example 1, since a sufficient temperature suppressing effect is obtained without spraying the coating agent, the coating agent is not used.

(Example 2)
In FIG. 7, the schematic top view of the coal pile 1 in Example 2 is shown. In Example 2, the shape of the coal pile 1 was almost the same as in Example 1, but the amount of coal stored was about 26,770 tons. Further, as in Example 1, a surfactant was sprayed on the coal pile 1, and the coating agent was not sprayed. In the same manner as in Example 1, with respect to the ceiling pressure, only the outer peripheral portion 13 of the ceiling surface was expanded, and the corner portion 16 was further expanded. As for the watering, as in Example 1, the watering only on the outer peripheral side surface 12 was divided into the initial watering and the subsequent regular watering. The amount of water spray in Example 2 is shown in Table 3 below. From the regular watering up to the 49th day, watering was not performed, and the temperature and moisture described below were measured over 49 days, and the effect of the coal pile 1 in Example 2 was confirmed.

Regarding the temperature, the temperature was measured using the thermocouple installed in the same manner as in Example 1 at the positions indicated by the encircled numerals 1 to 16 in FIG. 4, and the transition of the outer peripheral temperature of the coal pile 1 as the average value was measured. It was confirmed. In Example 2, the transition of the internal temperature of the coal pile 1 was further confirmed. After the initial watering, the internal temperature was measured by boring the ceiling surface 11 of the coal pile 1 at the positions shown in FIGS. 7A, 7B, 7C, and 5 thermocouples arranged at intervals of 1.5 m. The lower end thermocouple was buried so as to be 1.5 m above the ground (coal yard 2), and the average value of the temperatures measured by these three rows × 5 thermocouples was obtained.

FIG. 8 shows the transition of the outer and inner temperature of the coal pile 1. From FIG. 8, it can be seen that heat generation of the coal pile 1 is suppressed by the effect of watering, and both the outer temperature and the inner temperature are controlled at 40 ° C. or less throughout the coal storage period.

On the other hand, for the moisture, the outer peripheral moisture and the internal moisture were measured. Since the measurement of the peripheral moisture is the same as in Example 1, the description thereof is omitted here. Also, when boring when installing a thermocouple for measuring the internal temperature of the coal pile 1 and when the coal pile 1 is dismantled, a sample is taken from the inside of the coal pile 1, and the moisture measured for the sample is taken as the internal moisture. did.

FIG. 9 shows the transition of moisture in the coal pile 1. As shown in FIG. 9, the peripheral moisture increased by about 1 to 3% with respect to the received moisture, but when the internal moisture was confirmed when the coal pile 1 was disassembled, it was found that the increase was within 1% with respect to the received moisture. confirmed. From the above, in Example 2, it can be said that heat generation is suppressed without increasing the moisture of coal more than necessary.

(Example 3)
In Example 3, a coal pile was formed in the same shape as in Example 1 except that the amount of stored coal was about 19,664 tons, and the transition of the outer peripheral temperature of the coal pile was performed in the same manner as in Example 1. And the transition of the peripheral moisture was confirmed. In addition, about the outer peripheral temperature of coal pile, the transition of the maximum temperature was also confirmed besides the average temperature calculated | required similarly to Example 1. FIG. As for the spreading pressure, as in Example 1, only the outer peripheral portion of the ceiling surface was rolled on the ceiling surface, and the corner portion was further developed.

However, in Example 3, the surfactant was not sprayed on the coal pile and the coating agent was not sprayed. As for the watering, from the 3rd to the 16th day from the start of coal storage, watering was performed for 8 hours per day (176 tons in 8 hours), and regular watering was started from the 17th day. . Regular watering was divided into three periods. The first period was from the 17th to the 28th day from the start of coal storage, and watering was performed for 8 hours (176 tons in 8 hours) per 2 days. The second period was the period from the 31st to the 34th day from the start of coal storage, and watering was performed twice for 8 hours per week (176 tons in 8 hours). The third period was from the 38th day to the 45th day from the start of coal storage, and watering was performed for 8 hours per week (176 tons in 8 hours). The amount of water spray in Example 3 is shown in Table 4 below.

FIG. 10A shows a transition graph of the average temperature (outer periphery temperature) of the coal pile in Example 3. Moreover, in FIG. 10B, the transition graph of the maximum temperature (outer periphery temperature) of the coal pile in Example 3 is shown. Further, FIGS. 10A and 10B also show the moisture content of the coal in Example 3 and the moisture content on the outer periphery of the coal pile on the second and sixteenth days from the start of coal storage. From FIG. 10A, it can be seen that the heat generation of the coal pile is suppressed by the effect of watering, and the average temperature is controlled at 40 ° C. or less throughout the coal storage period. Moreover, FIG. 10B shows that the maximum temperature is also managed at 50 ° C. or lower, which is sufficiently lower than 60 ° C., which is the upper limit of the management temperature in coal storage. As for moisture, compared with Examples 1 and 2, although there is much increase in moisture relative to the moisture accepted, it has remained only a few percent increase, and heat generation is suppressed without increasing coal moisture more than necessary. It can be said.

(Comparative Example 1)
In FIG. 11, the schematic top view of the coal pile 1 in the comparative example 1 is shown. In Comparative Example 1, the shape of the coal pile 1 was almost the same as that of Example 1, but the amount of coal stored was about 18,000 tons. Further, as in Example 1, a surfactant was sprayed on the coal pile 1. However, in Comparative Example 1, unlike Example 1, watering to the coal pile 1 was not performed, and a coating agent was sprayed on the coal pile 1 in order to suppress pulverization of the coal pile 1. As a coating agent, Rikabond ET-39 manufactured by MC Evatech Co., Ltd. was used. The coating agent was sprayed using a portable power pump after installing a thermocouple for temperature measurement.

For temperature measurement, thermocouples are installed on the outer peripheral side surface 12 at the positions indicated by the circled numbers 1 to 42 in FIG. 11 (3 m high from the ground, 5 m apart horizontally, 1.5 m deep). The temperature at each position was measured, and the average value was taken as the temperature of the coal pile 1. In addition, unlike the example 1, the spreading pressure was performed on the entire surface of the ceiling surface 11.

FIG. 12 shows a temperature change graph of the coal pile 1 in Comparative Example 1. In Comparative Example 1, the temperature of the coal pile 1 continued to rise from the fifth day of coal storage, and reached about 60 ° C., which is the upper limit of the management temperature in coal storage, around 22 days, so temperature measurement was stopped. Moreover, since the watering is not performed in the comparative example 1, it turns out that a temperature rise cannot be suppressed also by spreading pressure and coating agent application.

(Comparative Example 2)
In FIG. 13, the schematic top view of the coal pile 1 in the comparative example 2 is shown. In Comparative Example 2, the shape of the coal pile 1 was a substantially square frustum shape, and the amount of coal stored was about 72,900 tons. As for the surfactant and the coating agent, as in Example 1, the surfactant was sprayed but the coating agent was not sprayed.

Also, in Comparative Example 2, contrary to Comparative Example 1, no spreading pressure was performed, and only watering to the outer peripheral side surface 12 was performed. Watering started on the fourth day of coal storage. However, since some charcoal was seen in 3 hours after sprinkling, for the time being, watering was performed for 3 hours per day, and the situation was observed, and from the 12th day of the start of coal storage, the watering was switched to 7 hours per day (initial watering). . The initial watering was conducted until the 18th day from the start of coal storage, and after the 19th day, the watering was switched to a regular watering of 7 hours per 2 days. However, during the period of regular watering, a temperature trend was observed, and from the 25th day, regular watering for 7 hours per day was carried out. Furthermore, on the 38th day, heat generation from other than the temperature measurement unit was confirmed. From the 38th day, it was changed to continuous watering for 24 hours per day. The amount of water spray in Comparative Example 2 is shown in Table 5 below.

FIG. 14 shows changes in the average temperature and the maximum temperature of the coal pile 1 in Comparative Example 2. The measurement of the temperature of the coal pile was performed in the same manner as in Example 1. From Fig. 14, the average temperature rises to about 50 ° C around the 14th day from the start of coal storage, and then tends to decline, but the maximum temperature is controlled between the 10th and 17th days. A temperature exceeding the temperature of 60 ° C. was confirmed. As described above, in Comparative Example 2, the effect of suppressing heat generation as in Examples 1 and 2 was not seen despite sprinkling water.

(Comparative Example 3)
In FIG. 15, the schematic top view of the coal pile 1 in the comparative example 3 is shown. In Comparative Example 3, as in Comparative Example 2, the shape of the coal pile 1 was a substantially square frustum shape, and the amount of coal stored was about 32,690 tons. Neither the surfactant nor the coating agent was sprayed.

In Comparative Example 3, a thermocouple was installed at a position indicated by circled numbers 1 to 4 in FIG. 15 and the temperature of the coal pile 1 was measured. The thermocouple installation method was the same as in Example 1. In Comparative Example 3, no spreading pressure was performed, and water was sprayed on the entire surface of the coal pile 1. A watering device (sprinkler) was installed at a position indicated by a circle in FIG. 15, and watering was carried out from the 13th day after the start of coal storage. Sprinkling was basically carried out at all times (24 hours), but depending on the temperature of the coal, etc., the days when watering was not carried out and the days when watering was carried out for about 6-7 hours per day were the coal storage period (70 days) There were only 9 days inside. In addition, sprinklers were added and removed according to the coal shipment status from coal pile 1 and the temperature status of coal pile 1. Shipment of coal from the coal pile 1 was performed sequentially from the upper left corner and the lower left corner shown in FIG. The amount of water spray in Comparative Example 3 is shown in Table 6 below.

FIG. 16 shows the transition of the maximum temperature of coal in Comparative Example 3. Referring to FIG. 16, since watering was not performed until the 12th day from the start of coal storage, the maximum temperature of the coal exceeded the control temperature of 60 ° C., and watering was performed from the 13th day. It can be seen that the temperature reached 79 ° C. The temperature decreased from the 15th day and decreased to 47 ° C. on the 16th day. From the 21st day onward, the temperature remained below 30 ° C.

Table 7 shows the conditions of Examples 1 to 3 and Comparative Examples 1 to 3 described above.

Table 8 shows data relating to the amount of coal and the amount of water sprayed in Examples 1 to 3 and Comparative Examples 1 to 3.

The amount of coal per 1 m ³ of water sprayed at the time of the maximum watering shown in Table 8 can be said to be one index representing the degree of heat generation suppression effect of coal by watering. That is, the greater the amount of coal per unit sprinkling amount, the more heat generation of a larger amount of coal can be suppressed with a smaller amount of sprinkling. In other words, the watering efficiency is excellent. From this point of view, referring to Table 8, it can be seen that all of Examples 1 to 3 are superior in watering efficiency as compared with Comparative Example 2.

(Summary)
From the examples and comparative examples described above, the following can be said.
(1) It was confirmed that by carrying out initial watering, heat generation of coal at the initial stage of coal storage can be suppressed and coal can be stored for a long time.
(2) It was confirmed that it was possible to manage without watering in about 1 to 2 months after shifting from initial watering to regular watering.
(3) It was confirmed that heat generation can be suppressed and moisture can be controlled without using a coating agent.
(4) It was confirmed that temperature control of the entire coal pile was possible even with watering only on the outer peripheral side.

DESCRIPTION OF SYMBOLS 1 Coal pile 2 Coal yard 11 Ceiling surface 12 Peripheral side surface 13 Ceiling surface outer peripheral part 14 Roadway 15 End part 16 Corner part

Claims

A yard for storing coal,
A frustum-shaped coal pile having a ceiling surface and an outer peripheral side surface formed by stacking the coal in the yard;
An expansion facility for expanding the coal pile;
A sprinkler for watering the coal pile;
With
The coal pile is characterized in that at least an outer peripheral portion of the ceiling surface is expanded by the expansion facility, and the outer peripheral side surface is sprinkled by the sprinkler.
2. The coal storage system according to claim 1, wherein corners of the coal pile are expanded on the outer peripheral side surface.
The coal storage system according to claim 1 or 2, further comprising at least one chemical spraying device for spraying chemicals on a surface of the coal or the coal pile.
The coal storage system according to any one of claims 1 to 3, wherein the pressure-expanding equipment is a heavy machine.
Forming a frustum-shaped coal pile having a ceiling surface and an outer peripheral side surface by stacking coal in the yard;
Expanding the outer peripheral portion of at least the ceiling surface of the coal pile;
Watering the outer circumferential side of the coal pile that has been spread;
A method for storing coal.
The coal storage method according to claim 5, wherein the step of spreading the coal pile includes spreading a corner portion on the outer peripheral side surface.
In the process of watering the coal pile, the watering time per day is determined, and the watering frequency is 10 to 14 after the start of coal storage and is half the watering frequency from the first 10 to 14 days. The coal storage method of Claim 5 or 6 including this.
The coal storage method according to any one of claims 5 to 7, further comprising at least one step of spraying a chemical on a surface of the coal or the coal pile.
The coal storage method according to claim 8, wherein the step of spraying the chemical includes spraying a surfactant as a chemical on the coal before forming the coal pile.
The coal storage method according to claim 8 or 9, wherein the step of spraying the chemical includes spraying a coating agent for maintaining the shape of the coal pile as a chemical on the coal pile.